Substituted trimethylene cyclopropanes, salts thereof, intermediates and methods of making the same

ABSTRACT

Trimethylenecyclopropane wherein all six hydrogen atoms are symmetrically substituted with cyano, alkoxycarbonyl or carbacyl groups and which are salt-forming can be made by reacting tetrachlorocyclopropene with the appropriate active methylene compound such as malononitrile, acetyl acetone or ethyl cyanoacetate. Using limited amounts of malononitrile and a tertiary amine, a tetracyanodimethylenecyclopropene substituted with a quaternary ammonium group is obtained, which reacts with other active methylene compounds including the above, nitroalkanes, benzoylacetonitrile, benzenesulfonylacetonitrile, and dialkyl sulfones to form unsymmetrical substituted trimethylenecyclopropane. The neutral compounds are useful as organic oxidants. Their radical anion salts are useful as organic conductors and as dyes, and the dianion salts are useful as image formers on transparent films or on opaque substrates.

RELATIONSHIP TO OTHER APPLICATIONS

This application is a divisional application of copending applicationSer. No. 535,138, filed Dec. 20, 1974, Pat. No. 3,963,769.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to novel negatively substitutedtrimethylenecyclopropanes, their radical anions and dianions, tointermediates therefore and to methods of making the same.

2. Prior Art

Trimethylenecyclopropane and its hexamethyl derivative have beenreported by Waitkus et al. (J. Am. Chem. Soc. 1967, 89, 6318) and others(Kobrich et al., Tetrahedron 1967, 23, 565; Bleiholder & Shechter, J.Am. Chem. Soc. 1964, 86, 5032; Kobrich & Heinemann, Angew. Chem. 1965,77, 590). Triquinocyclopropanes have been reported by West and Zecher(J. Am. Chem. Soc. 1967, 89, 152; 1970, 92, 149, 155).Triaminocyclopropenium ions and negatively substituted methylene(diamino) cyclopropenes derived from them have been reported by Yoshidaet al. (J. Am. Chem. Soc. 1971, 93, 2573; Topics in Current Chemistry,Springer-Verlag, New York, Vol. 40, 1973, pp. 47-72).

SUMMARY OF THE INVENTION

The present invention comprises compounds of the formula ##STR1##wherein X and Y are electron withdrawing groups selected from --CO(lower alkyl) or --COO (lower alkyl); and L and Q can be selectedindependently from --CO (lower alkyl) or --COO (lower alkyl) or pairwisefrom hydrogen and nitro; lower alkyl and nitro; hydrogen and lower alkylsulfono; or lower alkyl and lower alkyl sulfono.

This invention also comprises salts M^(+Z) ⁻ and M₂ ⁺ Z² ⁻ wherein Z⁻ isa radical anion formed by the addition of 1 electron, and Z² ⁻ is adianion formed by the addition of two electrons to a compound of theabove formula. M⁺ is one equivalent of cation inert to the anions,preferably alkali metal ions, tetra(lower alkyl)ammonium ions, andpyridinium ions.

This invention also comprises intermediates for making the abovecompounds having the formula ##STR2##

This invention further encompasses the method of making compounds of theformula ##STR3## which comprises contacting and reacting, in an inertsolvent, tetrachlorocyclopropene with a reagent of the formula CH₂ XY inthe presence of a strong, non-nucleophilic base at a temperature in therange between -50° C. and 100° C.

This invention further comprises a method of making compounds of theformula ##STR4## by contacting and reacting tetrachlorocyclopropene withCH₂ XY and N(lower alkyl)₃ in the molar ratios 1:2-3:5-6, at atemperature of -50° C. to 20° C. in an inert solvent.

Further, this invention comprises contacting and reacting ##STR5## withthe reagent CH₂ (LQ) in the presence of a strong, non-nucleophilic base,in the molar proportions 1:1-2:2-2.5 at a temperature in the range of 0°C. to 30° C. and in an inert solvent, to obtain compounds of the formula##STR6##

DETAILED DESCRIPTION OF THE INVENTION

The invention relates to a series of interrelated compounds and ionsderived therefrom having the formulas: ##STR7##

In the above formulas, each X can be cyano (-CH), alkoxycarbonyl##STR8## where R is lower alkyl, i.e., C₁ --C₆ alkyl; or preferably whentwo methylene groups are substituted with four cyano, the remaining X's,respectively, are hydrogen and nitro (-NO₂); phenyl and cyano;phenylacetyl and cyano; or benzosulfonyl and cyano; hydrogen and loweralkyl sulfono; or lower alkyl and lower alkyl sulfono.

The neutral trimethylenecyclopropenes of formula I have strong oxidationpower and, in many instances, are unstable in air or in solution,reverting rapidly to the radical anion form of formulas II-a and II-b.Analytically pure samples can be held indefinitely only in the instanceof hexa(methoxycarbonyl)trimethylenecyclopropane.

Certain radial anion compounds of formulas II-a and II-b are isolatablein the form of their salts, and all are generally detectable viapolarographic half-wave potentials obtained during oxidation of thedianion form.

The dianion compounds of formulas III-a and III-b are readilyinsolatable in the form of their salts and in certain instances in theform of the conjugate diacids. The bis(tetrabutylammonium) [TBA] saltsare especially useful for purification and characterization of thedianion species, and for their initial isolation.

Any cation inert to the anions can be employed to form salts includinghydrogen ions, alkali metal ions, alkaline earth metal ions, tetra(loweralkyl) ammonium ions, pyridinium, quinolinium, tetrathiofulvalinium andlike ions.

Ions which can exist in more than one value can be used to form salts ofthe radial anions or the dianion form provided that the redox potentialof the cation is such that the selected anion is neither oxidized orreduced by the cation. The redox potentials of the dianions and anionradical species vary substantially with the substituents selected asshown by the Table I when the substituents are selected from cyano (CN)and methoxycarbonyl (COOCH₃) groups.

                  Table I                                                         ______________________________________                                         ##STR9##                                                                     X.sub.1                                                                            X.sub.2                                                                              X.sub.3                                                                              X.sub.4                                                                            X.sub.5                                                                            X.sub.6                                                                            E.sub.1  E.sub.2                            ______________________________________                                        CN   CN     CN     CN   CN   CN   +0.34    +1.13                              CN   CN     CN     CN   CN   E    +0.26    +1.0                               CN   CN     CN     CN   E    E    +0.11    --                                 CN   CN     CN     E    CN   E    +0.17    +0.97                              CN   E      CN     E    CN   E    +0.10    +0.72                              CN   CN     E      E    E    E    +0.06    +0.46                              CN   E      CN     E    E    E    +0.05    +0.44                              CN   E      E      E    E    E    -0.01    +0.32                              E    E      E      E    E    E    -0.07    +0.16                              ______________________________________                                    

Complex cations are also within the contemplation of this invention.

When the reaction to form the dianion compound is conducted with astrong base, the cation is ordinarily derived from the base, e.g., whensodium hydride, the preferred base is employed in non-aqueous solutions,the sodium salt of the dianion will be formed. However, other cationscan be readily substituted by selection of the base or by conventionalmetathetical ionic reactions, e.g., crystallization of the dianioncompound in the presence of an excess of a salt of the selected cation,by precipitation with certain salts such as tetrabutyl ammonium chloridesince the tetrabutyl ammonium salts tend to be scarcely soluble inwater; by the use of ion exchange resins or the like.

In this specification, the term "lower alkyl" refers to alkyl radicals,including branched alkyl radicals of up to six carbon atoms.

The interrelated compounds and ions of formulas I, II and III areprepared via the reaction of tetrachlorocyclopropene with appropriateactive methylene compounds (CH₂ X₂) in suitable single or stepwiseprocedures, depending upon the desired assortment and location of Xsubstituents.

The single step method of preparing symmetrically substituted dianionictrimethylenecyclopropenes can be illustrated as follows, ##STR10##whereX and Y, individually, are the strongly negative (e⁻ withdrawing) groupsCN, CO₂ R or COR, R being lower alkyl. Representative active methylenereactants are malononitrile, dimethyl malonate, dibutyl malonate, methylcyanoacetate, hexyl cyanoacetate, acetylacetone, methyl acetoacetate,ethyl acetoacetate and acetylacetonitrile. The reaction proceeds withdisplacement of Cl⁻ with ^(-CHXY) followed by deprotonation by excessbase. The product may be conveniently isolated as an alkali metal ortetraalkylammonium salt, or as a conjugate acid released throughprotonation by a strong acid such as hydrochloric acid. In the originaldeprotonation, carried out in an anhydrous medium, sodium hydride is aneffective and preferred base, but other strong nonnucleophilic bases canbe used. In some instances a tertiary amine such as triethylamine is asuitable deprotonating base.

The reaction can be accomplished at temperatures in the range of about-50° to about +100°, preferably at a temperature in the range of 0°-25°.A preferred reaction medium is anhydrous 1,2-dimethoxyethane, and othersuitable solvents are diethyl ether, dimethylformamide,hexamethylphosphoramide and dimethyl sulfoxide.

The bases employed are those which are known to be capable ofabstracting active hydrogen atoms from the compounds containing activemethylene groups which are employed, i.e., bases which are effective insuch well-known reactions as the Dieckmann reaction, the Michaelreaction, or like condensations with active methylene compounds.

The reaction can be conveniently conducted at atmospheric pressure, butother pressures can be employed if desirable.

The stepwise method of preparing negatively substitutedtrimethylenecyclopropanes involves the initial reaction oftetrachlorocyclopropene with a restricted amount of an appropriateactive methylene compound together with an excess of a tertiary amine(R₃ N, R being lower alkyl) as HCl scavenger. This method can beillustrated as follows: ##STR11##

In reaction B the mole ratios of the three respective reactants isgenerally 1 to 2-3 to 5-6. If a large excess of CH₂ XY is used, atrimethylenecyclopropane can also be produced via reaction A.Triethylamine is a preferred tertiary amine. The reaction is carried outat a temperature in the range of -50° to +20°, and aproticnonnucleophilic solvents such as chlorohydrocarbons (especiallymethylene chloride), diethyl ether, tetrahydrofuran, acetonitrile anddimethylformamide can be used. Ambient pressure is suitable and ispreferred.

In reaction C the range of active methylene reactants (CH₂ LQ) can beextended beyond that of the active methylene reactants (CH₂ XY) usablein reaction A. Thus L and Q, individually, can be CN, COR or CO₂ R, Rbeing lower alkyl and the same or different to X and Y and, in pairs,can also be hydrogen or alkyl and nitro (as in nitromethane ornitroethane), phenyl and cyano (as in benzyl cyanide), benzoyl and cyano(as in benzoylacetonitrile), benzenesulfonyl and cyano (as inbenzenesulfonylacetonitrile), or hydrogen or alkyl and alkylsulfono (asin dimethyl sulfone or diethyl sulfone). This reaction involveselimination of NR₃ and subsequent deprotonation by the base originallyassociated with CHLQ⁻. A reaction temperature in the range from about 0°to about 30° is suitable; and slightly more than two equivalents ofCHLQ⁻ are generally used, but one equivalent of CHLQ⁻ can be used in thepresence of an additional equivalent of a base such as sodium hydride,or sodium methoxide. A combination of excess CH₂ LQ with NR₃ can also beemployed. The product can be conveniently isolated as thebis(tetrabutylammonium) salt or, in some instances, as the conjugatediacid. Suitable solvents are alcohols, hexamethylphosphoramide,dimethylformamide, and dimethyl sulfoxide.

In procedures A and C the trimethylenecyclopropane product is obtainedin the dianion form and is normally isolates as a salt, usually thebis-TBA salt. Formation of the radical ion and neutral forms requiresoxidation, the existence of these generally unstable oxidized formsbeing readily observed via polarographic halfwave potentials. Foroxidation to the radical ion form a persulfate, such as sodium orpotassium persulfate, bromine, iodine, chlorine, N-bromo-,N-iodosuccinimide, and periodate are suitable oxidizing agents, andcertain radical anion salts [e.g., of hexacyanotrimethylenecyclopropane,methoxycarbonylpentacyanotrimethylenecyclopropane andtris(methoxycarbonylcyanomethylene)cyclopropane] can be successfullyisolated. Otherwise, presence of radial anions is clearly indicated bythe formation of intensely colored (generally blue) solutions even ifisolation of salts is not readily achieved. Formation of the neutralform, which is even more unstable in may instance than the radical anionform, can be achieved by means of oxidants such as persulfate (S₂ O₈ ⁻),bromine (Br₂), iodine (I₂), poriodate (IO₄ ⁻), and thallium [Tl(III)].Characterization of the neutral form through isolation and conventionalanalysis has not proven easy and so far has been achieved completelyonly with hexa(methoxycarbonyl)trimethylenecyclopropane and partiallywith hexacyanotrimethylenecyclopropane.

The neutral compounds of the present invention are useful as oxidants.The radical anion salts are useful as electrical conductors and asdyestuffs for such fabrics as acetate acrylan, nylon, silk or wool, andthe dianion salts are useful for photoimaging, and for printing.

Specific Embodiments

This invention is further illustrated by the following specificembodiments, which should not be construed as fully delineating thescope thereof.

EXAMPLE 1 Hexacyanotrimethylenecyclopropanediidc ##STR12## A.Tetrabutylammonium Salt

To a suspension of 45 g of 53% sodium hydride in 850 ml of anhydrous1,2-dimethoxyethane (glyme) was added dropwise a solution of 30.0 g ofmalononitrile (purified by distillation) in 100 ml of anhydrous glyme at0° over a 35-minute period. The mixture was stirred at 0° for 1 hour anda solution of 25 g of tetrachlorocyclopropene in 50 ml of anhydrousglyme was added dropwise at 0° over a 30-minute period. The yellowsuspension was stirred at 0° for 1 hour and then decomposed carefullywith water. The resulting mixture was dissolved in 500 ml of water andtreated with a solution of 100 g of tetrabutylammonium bromide (TBABr)in 100 ml of water. The precipitated pale yellow solid was filtered,washed thoroughly with water and air-dried. A recrystallization fromethyl acetate:acetonitrile (3:1) gave 94.4 g (94%) ofbis(tetrabutylammonium) hexacyanotrimethylenecyclopropanediide ascolorless crystals; mp, 210°-213°.

Anal. Calcd for C₄₄ H₇₂ N₈ : C, 74.11; H, 10.18; N, 15.71 Found: C,74.14; H, 10.27; N, 16.17.

Uv (ch₃ cn): 315 nm ( ε = 22,500), 222 (35,800). IR (KBr): 4.57, 4.61,7.05 μ.

Oxidation potential (CH₃ CN): +0.34, +1.13 V (vs SCE).

The TBA salt was also prepared from an isolated sample of thecorresponding disodium salt (see Example 1-B) by treatment with TBABr inwater.

B. Sodium Salt

To a suspension of 4.0 g of sodium hydride in 100 ml of anhydrous glymewas added a solution of 2.8 g of malononitrile in 10 ml of the samesolvent at 0°. The mixture was stirred at 0° for 10 minutes and asolution of 2.5 g of tetrachlorocyclopropene in 10 ml of glyme was addeddropwise at 0°. The yellow suspension was stirred at 0° for 1 hour anddecomposed with 10 ml of saturated sodium chloride solution. Theprecipitated solid was filtered and recrystallized from 150 ml of waterto give 2.7 g (71%) of disodium hexacyanotrimethylenecyclopropanediideas colorless solid.

Anal. Calcd for Na₂ C₁₂ N₆ : C, 52.57; H, 30.65; Na, 16.77 for Na₂ C₁₂N₆.1/3 H₂ O: C, 51.44; N, 30.00; Na, 16.41 Found: C, 51.44; N, 30.76;Na, 16.21.

Uv (c₂ h₅ oh): 315 nm ( ε = 36,600); 221 (41,300).

C¹³ -nmr [dmso-d₆ /Cr(Acac)₃ ]: ⊕ 24.8, 121.0, 124.5 ppm (1:2:1)

Oxidation potential (CH₃ CN): +0.34, +1.13 V (vs SCE)

The disodium salt was also obtained by treatment of the correspondingbis-TBA salt with excess sodium iodide in acetonitrile and by reactionof 1,2-bis(dicyanomethylene)-3-triethylammoniumcyclopropanide (seeExample 5) with sodio malononitrile.

The disodium salt was converted to the dipotassium salt by treatmentwith potassium iodide in hot water.

EXAMPLE 2 Tris-(methoxycarbonylcyanomethylene)cyclopropandiide ##STR13##A. Bis(tetrabutylammonium) Salt

The title salt was prepared in the manner similar to that described inExample 1-A. The reaction mixture was evaporated under reduced pressureto dryness. The residue was dissolved in water, filtered, washed oncewith ether and treated with TBA bromide. The precipitated pale yellowsolid was filtered and recrystallized from ethyl acetate containing asmall amount of acetonitrile. From 10 g of tetrachlorocyclopropene and18 g of methyl cycanoacetate there was obtained an 85% yield of thedesired TBA salt, mp, 166°-170°, in two crops. An analytical sample,prepared by a further recrystallization from the same solvent mixture,was obtained as colorless crystals, mp, 168°-170°.

Anal. Calcd for C₄₇ H₈₁ N₅ O₆ : C, 69.50; H, 10.05; N, 8.62 Found: C,68.80; H, 9.99; N, 8.21.

Uv (ch₃ cn): 328 nm ( ε = 39,200), 232 (32,300). IR (KBr): 4.60, 6.15,7.09, 7.68, 8.54, 9.23 μ. Oxidation potential (CH₃ CN): +0.10, +.72 V(vs SCE).

B. Disodium Salt

Treatment of the above TBA salt with sodium iodide in acetonitrile gavethe corresponding disodium salt, an aqueous solution of whichreprecipitated the TBA salt on treatment with TBA bromide.

EXAMPLE 3 Hexa(methoxycarbonyl)trimethylenecyclopropandiide ##STR14## A.Conjugate Diacid

To a suspension of the sodium salt of dimethyl malonate, prepared from16.5 g of 50% sodium hydride and 24 g of dimethyl malonate in 340 ml ofanhydrous glyme, was added a solution of 10 g of tetrachlorocyclopropenein 20 ml of anhydrous glyme, dropwise at 0°-12°. The resulting thickyellow suspension was stirred at 20° for 1.5 hours, and the excesssodium hydride was decomposed by methanol. The yellow solid wascollected by filtration and washed with methanol. The crude disodiumsalt was dissolved in water and acidified with 6N hydrochloric acid. Theprecipitated solid was filtered, washed with water, air-dried andrecrystallized from carbon tetrachloride to give 13.7 g (57%) of theconjugate diacid of hexa(methoxycarbonyl)trimethylenecyclopropandiide ascolorless crystals, mp, 121°-123°.

Anal. Calcd for C₁₈ H₂₀ O₁₂ : C, 50.47; H, 4.71 Found: C, 50.60; H,4.84.

Uv (ch₃ cn): 300 nm (sh) (ε = 2500), 249 (22,400), 206 (11,400).

Ir, (kbr): 5.31, 5.65, 5.75, 6.45, 6.95, 7.54, 7.95, 8.35, 9.28, 9.75 μ.

B. Disodium Salt

The disodium salt was obtained as colorless powder either by treatmentof the above conjugate diacid with sodium methoxide in methanol or byreduction of hexa(methoxycarbonyl)trimethylenecyclopropane (Example 20)by sodium iodide in acetonitrile.

Anal. Calcd for Na₂ C₁₈ H₁₈ O₁₂.sup.. H₂ 0: C, 44.09; H, 4.11 Found: C,44.03; H, 4.53.

Ir (kbr): 2.90, 5.95, 6.95, 7.40, 8.40, 9.02 μ.

C. Bis(tetrabutylammonium) Salt

A solution of 1.0 mM of the above conjugate diacid in 20 ml of 0.1 M TBAhydroxide solution in benzene:methanol (9:1) was evaporated. The oilyresidue was crystallized in ethyl acetate to give 818 mg (90%) of thebis(TBA) salt as colorless solid. An analytical sample was prepared by arecrystallization from ethyl acetate:acetonitrile (10:1), mp, 222.5-224.5°.

Anal. Calcd for C₅₀ H₉₀ N₂ O₁₂ : C, 65.90, H, 9.96; N, 3.07 Found: C,66.12; H, 10.01; N, 2.95.

Uv (ch₃ cn): 303 nm (ε = 38,600), 267 (31,400).

Ir (kbr): 5.90, 5.95, 7.07, 7.50, 8.48, 9.25 μ.

D. Bis(tetramethylammonium) and Bis(tetraethylammonium) Salts

The conjugate diacid (one equivalent) was dissolved in two equivalentsof 10% aqueous solution of tetramethylammonium hydroxide and likewise oftetraethylammonium hydroxide. The solutions were evaporated in vacuo andthe residual oils were crystallized in ethyl acetate. Recrystallizationfrom acetonitrile - ethyl acetate gave analytical samples.Bis(tetramethylammonium) Salt: mp 292°-295°

Anal. Calcd for C₂₆ H₄₂ N₂ O₁₂ : C, 54.34; H, 7.37; N, 4.88 Found: C,54.44; H, 7.55; N, 4.98.

Bis(tetraethylammonium) Salt: mp 255-257°

Anal. Calcd for C₃₄ H₅₈ N₂ O₁₂ : C, 59.45; H, 8.51; N, 4.08 Found: C,59.52; H, 8.64; N, 4.14.

EXAMPLE 4 Hexaacetyltrimethylenecyclopropandiide ##STR15## ConjugateDiacid

To a suspension of sodium acetylacetonate prepared from 8.5 g of 53.5%sodium hydride and 18.0 g of acetylacetone in 220 ml of anhydrous glymewas added a solution of 5.0 g of tetrachlorocyclopropene in 10 ml ofanhydrous glyme at 0°. The resulting yellow suspension was stirred at 0°for 1 hour, diluted with water and washed once with methylene chloride.The aqueous solution was acidified with dilute hydrochloric acid andextracted with methylene chloride three times. The combined extractswere dried (MgSO₄) and evaporated. The residual solid was recrystallizedfrom benzene to give 1.92 g (21%) of the conjugate diacid ofhexaacetyltrimethylenecyclopropandiide as colorless crystals, mp,158°-160°; mass spectrum, m/e 332.1261 (calcd for C₁₈ H₂₀ Oμ, 332.1259);222.0871 (calcd for C₁₂ H₁₄ O₄, 222.0891); 179:0702 (calcd for C₁₀ H₁₁O₃, 179.0707).

Anal. Calcd for C₁₈ H₂₀ O₆ : C, 65.05; H, 6.06 Found: C, 64.24; H, 5.93.

EXAMPLE 5 1,2-Bis(dicyanomethylene)-3-triethylammoniumcyclopropanide##STR16##

To a well stirred solution of 25 g of tetrachlorocyclopropene and 20 gof malononitrile in 650 ml of methylene chloride was added 80 g oftriethylamine dropwise at -30°. The yellow mixture was slowly warmed to0°, treated with 200 ml of water and filtered. The solid wassuccessively washed with water, methanol and methylene chloride to give32 g (86%) of the inner salt as slightly brownish solid. An analyticalsample was prepared by a recrystallization from acetonitrile andobtained as colorless crystals: dec above 130°; mol weight (cryoscopicin DMSO), 263.

Anal. Calcd for C₁₅ H₁₅ N₅ : C, 67.90; H, 5.70; N, 26.40 Found: C,68.15; H, 5.75; N, 26.48.

Uv (ch₃ cn): 285 nm (ε = 32,600).

Ir (kbr): 4.50, 5.28, 6.55 μ.

EXAMPLE 61,2-Bis[di(methoxycarbonyl)methylene]-3-triethylammoniumcyclopropanide##STR17##

A solution of 25 g of tetrachlorocyclopropene and 41 g of dimethylmalonate in 600 ml of methylene chloride was treated with 77 g oftriethylamine at -30°. The mixture was warmed to O°, washed with waterthree times, and dried (MgSO₄). The solvent was evaporated and theresidual solid was recrystallized from ethyl acetate to give 28 g (50%)of the desired inner salt as tan solid. An analytical sample, mp185°-189° dec, was obtained as colorless crystals by a recrystallizationfrom ethyl acetate.

Anal. Calcd for C₁₉ H₂₇ NO₈ : C, 57.42; H, 6.85; N, 3.53 Found: C,57.58; H, 6.86; N, 3.51.

Uv (ch₃ cn): 306 nm (μ = 35,200), 236 (15,400).

Ir (kbr): 5.37, 5.88, 6.00, 6.70, 6.95, 7.55, 8.85, 9.15 μ.

EXAMPLE 71,2-Bis(methoxycarbonylcyanomethylene)-3-triethylammoniumcyclopropanide##STR18##

This inner salt was prepared in the manner similar to that described inExample 6. From 10 g of tetrachlorocyclopropene, 13 g of methylcyanoacetate and 35 g of triethylamine there was obtained 15.2 g (82%)of the desired salt as tan solid. An analytical sample was obtained ascolorless crystals, mp 227° dec (from 220° bath), by a recrystallizationfrom acetonitrile. Anal. Calcd for C₁₇ H₂₁ N₃ O₄ : C, 61.62; H, 6.39; N,12.69 Found: C, 61.71; H, 6.13; N, 12.80.

Uv (ch₃ cn): 297 nm (ε = 37,100), 235 sh (5980), 207 (23,600);

Ir (kbr): 4.52, 5.33, 5.90, 6.75, 6.96, 7.74, 8.42, 9.00, 9.18 μ.

EXAMPLE 8Bis(dicyanomethylene)(methoxycarbobylcyanomethylene)cyclopropandiide##STR19## A. Bis(tetrabutylammonium) Salt

A solution of the sodium salt of methyl cyanoacetate was prepared from6.0 g of sodium methoxide and 11.0 g of methyl cyanoacetate in 350 ml ofmethanol and treated with a solution of 13.5 g of the tetracyano innersalt (see Example 5) in 130 ml of hexamethylphosphoramide at 0° over a1-hour period. The brown solution was stirred at 0° for 1 hour, then 60g of TBA bromide was added. The methanol was evaporated under reducedpressure and the brown oily residue was allowed to stand at 20°overnight. The precipitated yellow solid, filtered and washed with ethylacetate and water, weighed 27.7 g (73%). From the filtrate, a secondcrop (2.7 g) was obtained. Successive recrystallizations from ethylacetate: acetonitrile and from dichloroethane gave an analytical sampleof bis(tetrabutylammoniummethoxycarbonylpentacyanotrimethylenecyclopropandiide as pale yellowprisms, mp, 209°-211°.

Anal. Calcd for C₄₅ H₇₅ N₇ O₂ : C, 72.44; H, 10.13; N, 13.14 Found: C,72.26; H, 9.97; N, 13.06.

Uv (ch₃ cn): 322 nm (ε = 34,400), 224 (32,600).

Ir (kbr): 4.59, 4.64, 6.10, 7.07, 7.61, 8.60, 9.20 μ. Oxidationpotential (CH₃ CN): +0.26, +1.0 V (vs SCE).

B. Disodium Salt

The above bis-TBA salt was converted to the disodium salt by treating itwith sodium iodide in acetonitrile.

EXAMPLE 91,2-Bis(dicyanomethylene)-3-di(methoxycarbonyl)methylenecyclopropandiide##STR20## A. Bis(tetrabutylammonium)Salt

To a solution of sodio dimethyl malonate prepared from 1.5 g of 53.5%sodium hydride and 1.5 g of dimethyl malonate in 60 ml of anhydrousglyme was added a solution of 2.6 g of the tetracyano inner salt(Example 5) in 20 ml of hexamethylphosphoramide, dropwise at 0° . Thebrownish yellow mixture was stirred at 0° for 1.5 hours and then waterwas added to dissolve the precipitated yellow solid. The aqueoussolution was washed once with methylene chloride, then treated with anaqueous solution of 10 g of TBA bromide. The precipitated yellow solidwas filtered and recrystallized from ethyl acetate:acetonitrile to give2.88 g (38%) of the bis-TBA salt as golden yellow crystals, mp,234°-236°.

Anal. calcd for C₄₆ H₇₀ N₆ O₄ : C, 70.91; H, 10.09; N, 10.79 Found: C,70.81; H,10.27; N, 10.76.

Uv (ch₃ cn): 322 nm (ε = 32,800); 269 (17.200); 223 (27,600)

Ir (kbr): 4.60, 4.65, 5.90, 6.22, 7.10, 7.50, 8.45, 9.00, 9.28 μ

Oxidation potential (CH₃ CH): 0.11 eV (vs SCE).

B. Disodium Salt

The above bis-TBA salt was treated with sodium iodide in acetonitrile togive the corresonding disodium salt as pale green tinted colorlesssolid.

EXAMPLE 101,2-Bis(methoxycarbonylcyanomethylene)-3-dicyanomethylenecyclopropandiide##STR21## Bis(tetrabutylammonium) Salt

To a solution of sodio malononitrile prepared from 2.4 g of sodiummethoxide and 2.9 g of malononitrile in 160 ml of methanol was added asolution of 6.4 g of the diester dicyano inner salt (Example 7) in 190ml of hexamethylphosphoramide, dropwise at 0° . The reaction mixture waswarmed to room temperature and stirred for 2.5 hours. The dark orangesolution was treated with 30 g of TBA bromide and the methanol wasevaporated. The residual solution was diluted with water to 700 ml andthe precipitated yellow solid weighed 4.57 g (30.4%). Arecrystallization from ethyl acetate:acetonitrile gave 4.13 g of thebis-TBA salt as yellow crystals; mp, 141°-143°.

Anal. Calcd for C₄₆ H₇₈ N₆ O₄ : C, 70.91; H, 10.09; N, 10.79 Found: C,71.19; H, 9.92; N, 10.83.

Uv (ch₃ cn): 326 nm (ε = 25,400); 227 (30,000).

Ir (kbr): 4.57, 4.63, 6.10, 7.08, 7.64, 8.55, 9.19 μ.

Oxidation potential (CH₃ CN): +0.17, + 0.97 V (vs SCE).

EXAMPLE 111,2-Bis(methoxycarbonylcyanomethylene)-3-di(methoxycarbonyl)-methylenecyclopropandiide##STR22## A. Monohydrogen Tetrabutylammonium Salt

A solution of sodio dimethyl malonate prepared from 2.4 g of sodiummethoxide and 5.9 g of dimethyl malonate in 160 ml of methanol wastreated dropwise with a solution of 6.7 g of thedicyanodimethoxycarbonyl inner salt (Example 7) inhexamethylphosphoramide at 0°-5° . The mixture was stirred at roomtemperature for 2 hours and then 30 g of TBA bromide was added. Themethanol was evaporated, and the oily residue was diluted with water,acidified with 6N hydrochloric acid, and extracted with ethyl acetatethree times. The combined extracts were washed with brine and dried(MgSO₄). The solvent was evaporated, and the residual solid was filteredand washed with ethyl acetate to give 8.2 g (68%) of colorless solid;mp, 104°-107° . A recrystallization from n-butyl chloride gave ananalytical sample of the monohydrogen TBA salt as colorless crystals;mp, 113°-115°.

Anal. Calcd for C₃₂ H₄₉ N₃ O₈ : C, 63.66; H, 8.18; N, 6.96 Found: C,63.56; H, 8.22; N, 7.08.

(ch₃ cn): 293 nm (ε = 40,900); 215 (sh) (19,800); 209 (20,600).

Ir (kbr): 4,55, 5.35, 5,73, 5.76, 5.97, 6.04, 6.76, 7,00, 7,70, 8.60,9.12 μ.

B. Bis(tetrabutylammonium) Salt

A two-phase solution of 603 mg of the above salt (Example 11-A) in 10 mlof 0.1N TBA hydroxide solution in benzene:methanol (9:1) was evaporatedand then taken up in ethyl acetate. The crystallized solid was filteredand recrystallized from ethyl acetate:acetonitrile to give 745 mg (88%)of the bis-TBA salt as colorless crystals; mp, 145.5°-147.0°.

Anal. Calcd for C₄₈ H₈₄ N₄ O₈ : C, 68.20; H, 10.01; N, 6.63 Found: C,68,22; H, 9.88; N, 6.82.

Uv (ch₃ cn): 320 nm (ε = 34,600): 305 (sh) (31,900); 234 (25,400).

Ir (kbr): 4.60, 5.85, 6.08, 6.71, 7.05, 7.12, 7.57, 7.65, 7.80, 8.40,8.60, 9.30 μOxidation potential (CH₃ CN): +0.05, + 0.44 V (vs SCE).

EXAMPLE 121,2-Bis[di(methoxycarbonyl)methylene]-3-dicyanomethylenecyclopropandiide##STR23## Bis(tetrabutylammonium) Salt

To a solution of sodio malononitrile prepared from 3.0 g of sodiummethoxide and 3.7 g of malononitrile in 175 ml of methanol was added asolution of 10.0 g of the tetraester inner salt (Example 6) in 125 ml ofmethanol, dropwise at 0° . The dark brown solution was stirred at 0° for2 hours, then 30 g of TBA bromide was added. The methanol was evaporatedand the oily residue was disolved in water and extracted with methylenechloride three times. The combined extracts were dried (MgSO₄) and thesolvent was evaporated. The residue was crystallized from ethyl acetateto give 8.62 g (40.5%) of the bis-TBA salt as yellow solid. Arecrystallization from ethyl acetate:acetonitrile gave an analyticalsample as colorless crystals; mp, 168°-171° .

Anal. Calcd for C₄₈ H₈₄ N₂ O₈ : C, 68.20; H, 10.02; N, 6.63 Found: C,67.73; H, 10.28; N, 6.54.

Uv (ch₃ cn): 315 nm (ε = 32,000); 268 (22,700).

Ir (kbr): 4.56, 4.62, 5.90, 7.00, 7.13, 7.50, 9.27, 11.33 μ.

Oxidation potential (CH₃ CN): +0.06, + 0.46 V (vs SCE).

EXAMPLE 131,2-Bis[di(methoxycarbonyl)methylene]-3-methoxycarbonyl-cyanomethylenecyclopropandiide##STR24## A. Bis(tetrabutylammonium) Salt

To a solution of sodio methyl cyanoacetate prepared from 3.0 g of sodiummethoxide and 5.5 g of methyl cyanoacetate in 175 ml of methanol wasadded a solution of 8.5 g of the tetraester inner salt (Example 6) in125 ml of methanol, dropwise at 0° . The solution was stirred at 0° for2 hours and then 30 g of TBA bromide was added. The methanol wasevaporated, the residue dissolved in 200 ml of water, and the aqueoussolution extracted with methylene chloride. After drying (MgSO₄) thesolvent was evaporated, and the solid residue was filtered and washedwith ethyl acetate to give 12.8 g (68.7%) of the bis-TBA salt ascolorless solid. The ethyl acetate filtrate was washed with water, dried(MgSO₄) and concentrated to give 2.8 g (20.9%) of the monohydrogen TBAsalt (see Example 13-B).

The crude bis-TBA salt was recrystallized from ethylacetate:acetonitrile to give colorless crystals; mp, 215°-218° .

Anal. Calcd for C₄₈ H₈₇ N₃ O₁₀ : C, 67.01; H, 9.99; N, 4.79 Found: C,66.80; H, 10.41; N, 4.84.

Uv (ch₃ cn): 315 (sh) nm (ε = 32,000); 299 (34,300); 238 (24,400).

Ir (kbr): 4.60, 5.90, 7.02, 7.13, 7.52, 8.48, 9.2-9.3, 11.36 μ.

Oxidation potential (CH₃ CN): -0.01, + 0.32 V (vs SCE).

B. Monohydrogen Tetrabutylamonium Salt

The title salt was obtained in Example 13-A, and also by treatment ofthe bis-TBA salt with dilute hydrochloric acid. A recrystallization fromethyl acetate gave an analytical sample as colorless crystals: mp,145°-147° .

Anal. Calcd for C₃₃ H₅₂ N₂ O₁₀ : C, 62.24; H, 8.23; N, 4.40 Found: C,62.46; H, 8.56; N, 4.66.

Uv (ch₃ cn): 294 nm (ε = 43,700); 222 (16,400).

Ir (kbr): 4.30, 5.37, 5.67, 5.85, 5.97, 7.00, 7.50, 7.80, 8.50, 9.05,9.30 μ.

EXAMPLE 14 1,2-Bis(dicyanomethylene)-3-nitromethylenecyclopropandiide##STR25## Bis(tetrabutylammonium) Salt

To a solution of 1.2 g of sodium methoxide in 60 ml of methanol wasadded a solution of 1.0 ml o nitromethane in 10 ml of methanol at 20° .The solution was cooled to 0° and a solution of 2.8 g of the tetracyanoinner salt (Example 5) in 30 ml of hexamethylphosphoramide was addeddropwise. The reaction mixture was stirred at 0° for 2 hours and thentreated with an aqueous solution of 10 g of TBA bromide. The pecipitatedsolid was filtered, washed with water and air-dried to give 3.7 g ofbrown solid. A recrystallization from ethyl acetate gave 138 mg (2.8%)of the bis-TBA salt as yellow brown crystals; mp, 178°-180° .

Anal. Calcd for C₄₂ H₇₃ N₇ O₂ : C, 71.24; H, 10.39; N, 13.85 Found: C,71.13; H, 10.62; N, 14.07 .

EXAMPLE 15 1,2-Bis(dicyanomethylene)-3-(α-cyanobenzylidene)cyclopropandiide ##STR26## Bis(tetrabutylammonium Salt

To a solution of sodium methylsulfinylmethide prepared from 1.0 g of 50%sodium hydride and 20 ml of dimethyl sulfoxide was added a solution of2.5 g of benzyl cyanide in 5 ml of dimethyl sulfoxide (DMSO) at 22° .After 30 minutes stirring at 22° , a solution of 2.7 g of the tetracyanoinner salt (Example 5) in 20 ml of DMSO was added dropwise at 10°-20° .The dark brown mixture was stirred at room temperature, poured into icewater, treated with 10 g of TBA bromide and extracted three times withmethylene chloride. The combined extracts were washed successively withwater and saturated salt solution and dried (MgSO₄). The solvent wasevaporated and the residual solid was recrystallized from ethylacetate:acetonitrile to give 6.2 g (80%) of the bis-TBA salt as yellowsolid. A recrystallization from ethyl acetate:acetonitrile (7:1) gave ananalytical sample; mp, 139°-142° C.

Anal. Calcd for C₄₉ H₇₇ N₇ : C, 77.01; H, 10.16; N, 12.83 Found: C,76.99; H, 10.02; N, 12.75.

Uv (ch₃ cn): 372 nm (ε = 28,000), 323 (20,000), 279 (16,800), 238(26,500).

Ir (kbr): 4.62, 6.25, 6.70, 6.88, 7.10, 7.17, 8.50, 10.31, 11.35 μ.

EXAMPLE 161,2-Bis(dicyanomethylene)-3-benzoylyanomethylenecyclopropandiide##STR27## Bis(tetrabutylammonium) Salt

The title salt was prepared in the manner similar to that described inExample 15. After the reaction mixture had been poured into water andtreated with TBA bromide, the mixture was stirred with ethyl acetate.The yellow solid was then filtered, washed with water and ethyl acetateand air-dried. From 3.1 g of benzoylacetonitrile and 2.7 g of thetetracyano inner salt, there was obtained 5.55 g (68.7%) of the bis-TBAsalt; mp, 126°-128° .

Anal. Calcd for C₅₀ H₇₇ N₇ O: C, 75.80; H, 9.80; N, 12.38 Found: C,75.92; H, 10,00; N, 12.67.

Uv (ch₃ cn): 375 nm (ε = 15,100); 305 (22,300); 224 (33,000).

Ir (kbr): 4.58, 6.28, 6.43, 7.05, 7.22, 7.45, 8.97, 11.27 μ.

EXAMPLE 171,2-Bis(dicyanomethylene)-3-benzenesulfonylcyanomethylenecyclopropandiide##STR28## Bis(tetrabutylammonium) Salt

The title salt was prepared in the manner similar to that described inExample 16. From 1.0 g of 50% sodium hydride, 2.5 g ofbenzenesulfonylacetonitrile and 2.7 g of the tetracyano inner salt,there was obtained, after a recrystallization from ethyl acetate, 4.75 gof the desired TBA salt; mp, 145°-147° .

Anal. Calcd for C₄₉ H₇₇ N₇ SO₂ : C, 71.05; H, 9.37; N, 11.84; S, 3.87;Found: C, 70.94; H, 9.50; N, 12.14; S, 3.86.

Uv (ch₃ oh): 308 nm (ε = 25,800), 219 (29,700).

Ir (kbr): 4,60; 7.10; 7.68, 8.47, 8.74, 9.18, 11.4, 13.85, 14.55 μ.

EXAMPLE 18 Hexacyanotrimethylenecyclopropane Radical Anion [C₆ (CN)₆ ]↑→ [C₆ (CN)₆ ]↑ A. Bis(tetrathiafulvalene) Salt, (C₆ 6H₄ S₄)₂ 8C₆ (CN)₆ ]

To a solution of 119 mg of tetrathiafulvalene* monochloride (TTF Cl) in150 ml of boiling ethanol was added a solution of 178 mg of the bis-TBAsalt of hexacyanotrimethylenecyclopropandiide in 20 ml of hot ethanol.The mixture was allowed to stand at room temperature for six days, andthen filtered to give 121 mg (75.6%) of (TTF)₂ [C₆ (CN)₆ ] as blackneedlets; mp, 233°-234°.

Anal. Calcd for C₂₄ H₈ N₆ S₈ : C, 45.26; H, 1.27; N, 13.20 Found: C,45.12; H, 1.29; N, 13.13.

Resistivity (compaction): 1 ohm cm.

Uv (ch₃ cn): 672 nm (ε = 15,000); 594 (14,400); 435 (20,700); 320(43,700); 215 (35,000).

Ir (kbr): 4.57, 7.00, 7.45, 8.90, 9.25 μ.

B. Potassium Salt

To a filtered solution of 15 g of potassium persulfate in 200 ml of warmwater was added a solution of 7.275 g of the disodium salt of thehexacyanodianion (Example 1-B). The mixture was cooled, filtered, washedwith water and dried in vacuo to give 6.653 g (94.5%) of potassiumhexacyanotrimethylenecyclopropanide as reddish maroon crystals withcopper-like luster. The radical anion salt does not melt but gives aburst of light on placing in a bath above 340°.

Anal. Calcd for KC₁₂ N₆ : C, 53.93; N, 31.45 Found: C, 53.79; N, 31.24.

Uv (ch₃ cn): 673 nm (ε = 19,900); 598 (12,900); 320 (30,500).

Resistivity (compaction): 3 × 10⁵ ohm cm.

Ir (kbr): 4.50, 6.70, 6.77 μ.

A polarographic study confirmed the composition and showed no dianion.The esr spectrum showed, in addition to the ¹⁴ N isotropic hyperfinesplitting (0.904G) and g value (2.00274), the splittings of 6.960, 9.945and 1.29G due to ¹³ C of CN, ¹³ C of methylene carbons and ¹⁵ N,respectively. No lines attributable to ¹³ C of ring carbons weredetected.

C. Tris(dimethylamino)cyclopropenium Salt

To a hot filtered solution of 610 mg oftris(dimethylamino)cyclopropenium hexafluorophosphate in 125 ml of waterwas added a hot solution of 520 mg of potassiumhexacyanotrimethylenecyclopropanide (Example 17-B) in 125 ml of water,through a fritted glass funnel. The still warm mixture was filtered andthere was obtained 190 mg (24.6%) of the 1:1 complex as dark purplesolid; mp, 162.5°-164.0°.

Anal. Calcd for C₂₁ H₁₈ No: C, 63.62; H, 4.58; N, 31.81 Found: C, 63.24;H, 4.53; N, 31.91.

Resistivity (compaction): 2 × 10⁷ ohm cm.

Uv (ch₃ cn): 673 nm (ε = 18,900); 598 (12,400); 540 (sh) (6220); 322(29, 500); 220 (38,600).

Ir (kbr): 4.52, 5.49, 6.41, 7.10, 8.20, 9.60 μ.

D. Tetrabutylammonium Salt

A solution of 1.3 g of the dianion TBA salt in 30 ml of methylenechloride was treated with 0.1 ml of bromine. The blue solution wasevaporated and the residue was taken up in water, filtered and washedwith water to give 1.3 g of black solid. A recrystallization from 95%ethanol gave an analytical sample of the radical anion TBA salt as darkpurple needles; mp, 124° dec.

Anal. Calcd for C₂₈ H₃₆ N₇ : C, 71.46; H, 7.71; N, 20.83 Found: C,71.64; H, 7.75; N, 20.56.

Resistivity (compaction): 3 × 10⁸ ohm cm.

Polarography (CH₃ CN): all anion radical and no dianion.

Uv (ch₃ cn): 673 nm (ε = 19,300), 598 (12,500), 320 (29,700), 215(25,000).

Ir (kbr): 4.51, 5.39, 6.72, 7.24, 11.28 μ.

E. Sodium Salts

A solution of 3.98 g of the dianion disodium salt in 70 ml of water wastreated with 0.81 ml of bromine, filtered, and washed successively withwater, alcohol and ether to give 2.73 g (73.6%) of Na₆ [C₆ (CN)₆ ]₅ asdark purple solid, which did not melt but gave a burst of light above370°.

Anal. Calcd for Na₆ (C₁₂ N₆)₅ : C, 56.31; N, 32.86 Found: C, 56.31; N,33.25.

Uv (ch₃ cn): 673 nm (ε per C₁₂ N₆ 20,000); 598 (13,000); 320 (30,700).

Ir (kbr): 4.50, 6.70, 7.00 μ.

Polarography (CH₃ CN): anion radical/dianion = 19 ± 2/81 ± 2.

Resistivity (compaction): 3× 10⁵ ohm cm.

Esr (thf): 11 line pattern (0.90 ± 0.01 G) (see Example 18-B).

The identical complex salt was obtained also from the dianion disodiumsalt and ferric chloride. Anal. Found: C, 56.19; N, 32.78.

A recrystallization from 95% ethanol gave the 3:2 salt, Na₃ [C₆ (CN)₆]₂, as blue solid; no melting and no high temperature flush.

Anal. Calcd for Na₃ (C₁₂ N₆)₂ : C, 54.87; N, 32.00; Na, 13.13 Found: C,54.61; N, 31.90; Na, 12.99.

Uv (ch₃ cn): 673 nm (ε per C₁₂ N₆ 10,200); 598 (6600); 320 (31,000).

Ir (kbr): 4.51, 4,58, 6.95 μ.

Polarography (CH₃ CN): dianion/anion radical = 1.08 ± 0.03.

Resistivity (compaction): 1 × 10⁴ ohm cm.

F. Pyridinium Salt

To a solution of 1.6 g of pyridinium bromide perbromide in 20 ml ofmethanol was added a solution of 1.35 g of disodiumhexacyanotrimethylenecyclopropandiide in 35 ml of water. The mixture wascooled, filtered and washed with water, methanol and ether. The brownsolid (1.153 g) was recrystallized from 95% ethanol to give 719 mg(46.7%) of the radical anion pyridinium salt as reddish maroon needleswith metallic luster; mp, 203° dec (from 200° preheated bath).

Anal. Calcd for C₁₇ H₆ N₇ : C, 66.23; H, 1.96; N, 31.81 Found: C, 66.17;H, 2.15; N, 30.62.

Resistivity (compaction): 1 × 10⁵ ohm cm.

Uv (ch₃ cn): 673 nm (ε = 19,800), 598 (12,700), 320 (30,300), 256(7860), 224 (24,900).

Ir (kbr): 4.51, 5.49, 6.10, 6.21, 6.50, 6.71, 11.35, 13.48, 14.95 μ.

G. Copper Salt

A solution of the dianion sodium salt was treated with cupric acetate (5eq.) in water. There was obtained a blue solid (91%), which analyzed asCu₂ [C₆ (CN)₆ ].sup.. 2H₂ 0. Anal. Calcd for Cu₂ C₁₂ H₄ N₆ 0₂ : C,36.83; H, 1.03; N, 21.48 Found: C, 36.80; H, 0.90; N, 21.01. UV (CH₃ CN): 673 nm (ε > 11,600); 598 (> 7600); 320 (> 23,800). IR (KBr): 2.90,4.52, 7.00, 8.80 μ. Resistivity (compaction): 7 × 10⁵ ohm cm.

EXAMPLE 19 Methoxycarbonylpentacyanotrimethylenecyclopropane AnionRadical [C₆ (CN)₅ (COOCH₃)]_(5/8)→[C₆ (CN)₅ (COOCH₃)]_(5/8) A. PotassiumSalt

To a warm solution of 4.0 g of potassium persulfate in 60 ml of waterwas added a solution of 2.0 g of the disodium salt (Example 8-B) in 50ml of warm water, through a fritted glass filter. The dark blue mixturewas cooled in ice bath, filtered, washed with water and dried in vacuoat 80° to give 870 mg (44.6%) of the anion radical potassium salthydrate as dark blue solid, which did not melt below 360°.

Anal. Calcd for KC₁₃ H₃ N₅ O₂.2/3 H₂ O: C, 49.99; H, 1.40; N, 22.43Found: C, 49.96; H, 1.37; N, 22.17.

Resistivity (compaction): 2 × 10⁶ ohm cm.

Uv (ch₃ cn): 668 nm (ε = 18,100); 592 (12,100); 325 (28,200); 218(21,800).

B. Tetrathiafulvalene Salt

A hot solution of 119 mg of tetrathiafulvalene monochloride in 150 ml ofethanol was mixed with a hot solution of 187 mg of the bis-TBA salt ofthe pentacyanomonoester dianion (Example 8-A) in 20 ml of ethanol. Theblue solution was allowed to stand at room temperature for 6 days. Therewas obtained 82 mg of the 1:1 complex as dark purple needlets; mp,223°-224°.

Anal. Calcd for C₁₉ H₇ N₅ S₄ O₂ : C, 49.01; H, 1.52; N, 15.04 Found: C,49.04; H, 1.62; N, 15.37.

Resistivity (compaction): 100 ohm cm. UV (CH₃ CN): 668 nm (ε = 19,300);590 (16,600); 435 (15,500); 325 (33,500); 217 (25,900).

EXAMPLE 20 Tris(methoxycarbonylcyanomethylene)cyclopropane Anion Radical[C₆ (CN,COOCH₃)₃ ]⁼ →[C₆ (CN,COOCH₃)₃ ] Potassium Salt

A solution of 3.7 g of the dianion disodium salt (Example 2-B) in 75 mlof water was added to a warm solution of 5.0 g of potassium persulfateand filtered immediately to give 3.16 g (86%) of the radical anionpotassium salt as bright blue solid; mp, 270° dec.

Anal. Calcd for KC₁₅ H₉ N₃ O₆ : C, 49.17; H, 2.48; N, 11.47 Found: C,48.71; H, 2.54; N, 11.59.

Resistivity (compaction): 2 × 10⁸ ohm cm. UV (CH₃ CN): 665 nm (ε >6560); 592 (> 4730); 336 (> 11,900); 223 (> 9300).

EXAMPLE 21 Hexa(methoxycarbonyl)trimethylenecyclopropane ##STR29##

The conjugate diacid (2.0 g) of the hexaester dianion (Example 3-A) wasadded in portions into a stirred solution of 2.0 g of sodium periodatein 100 ml of water. Stirring was continued until the brown solidcompletely turned bright yellow. The solid was extracted with methylenechloride, dried (MgSO₄) and the solvent evaporated. The residue wastaken up in ether, and the yellow solid was filtered and washed withether to give 1.35 g of the hexaester. A recrystallization from n-butylchloride afforded an analytical sample; mp, 137°-140°.

Anal. Calcd for C₁₈ H₁₈ O₁₂ : C, 50.71; H, 4.26 Found: C, 51.03; H,4.37.

Mass Spectrum: m/e 426.0805 (calcd for C₁₈ H₁₈ O₁₂ ; 426.0797).

Nmr (cdcl₃): 3.90 ppm (s)

Uv (ch₃ cn): 400 (sh) nm (ε = 16,300); 375 (20,700); 223 (13,700).

Ir (kbr): 3.36, 5.77, 6.95, 7.70, 8.1, 9.1, 9.6, 10.5, 12.1 μ.

Reduction potentials (CH₃ CN): -0.07, +0.022 V (vs SCE).

In some cases the crude oxidation product contained colorless solidinsoluble in n-butyl chloride and benzene. Two recrystallizations fromethyl acetate:acetonitrile afforded colorless crystals; mp, 220°-230°,which are assigned the dimeric structure shown below.

Anal. Calcd for C₃₆ H₃₈ O.sub. 24 : C, 50.59; H, 4.48 Found: C, 50.32;H, 4.45.

Mol. wt. (mass spec.): 854 (calcd: 854).

Nmr (cdcl₃): 3.70 (s), 5.73 (s), (12:6:1).

Uv (ch₃ cn): 300 (sh) nm (ε = 4980); 254 (39,900); 206 (23,200).

Ir (kbr): 5.31, 5.73 (br), 6.44, 6.95, 7.64, 7.95, 9.00, 9.35, 9.77,11.20 μ. ##STR30## where E is COOCH₃.

EXAMPLE 22 Hexacyanotrimethylenecyclopropane ##STR31##

To a solution of 3.0 g of thallium(III) trifluoroacetate in 30 ml oftrifluoroacetic acid and 5 ml of acetonitrile was added 1.0 g of Na₆ [C₆(CN)₆ ]₅ (Example 17-E). The dark green mixture was stirred under argon.To dissolve blue solid, 40 ml of acetonitrile, 2.0 g of thallium (III)trifluoroacetate and 10 ml of trifluoroacetic acid were added inportions. The mixture was stirred for 6 hours and then filtered underargon to give 725 mg of hexacyanotrimethylenecyclopropane as tan solid,which turned brown in air, gave greenish-blue color in organic solventsand became dark below 250° without melting.

Mass Spectrum: m/e 228.0192 (calcd for C₁₂ N₆ : 228.0174), 176; 152.

Ir (nujol): 4.50, 6.41, 8.20, 9.43 μ.

EXAMPLE 23 Photoimage Formation - Bis(tetrabutylammonium)Hexacyanotrimethylenecyclopropandiidc

Film prepared from a mixture consisting of 0.2 g of the title compound(Example 1-A), 5 ml of 10% solution of cellulose acetate butyrate inacetone, 0.2 g of2,2'-bis(o-chlorophenyl-4,4',5,5'-tetraphenylbisimidazole, 0.5 g of2,4-dichlorobenzaldehyde and 0.75 g of tricresyl phosphate was exposedto a sunlamp. Exposure to 100 μ joules/cm² light formed a blue imagewith 0.32 optical density.

EXAMPLE 24 Cloth Dye - Hexacyanotrimethylenecyclopropane Anion Radical

The potassium salt (Example 17) and the TBA salt (Example 17) gave blueor brown shades on acetate, acrylan, nylon, silk and wool.

EXAMPLE 25 Paper Printing - Bis(tetrabutylammonium)Hexacyanotrimethylenecyclopropandiide

A solution of the title compound (see Example 1-A) in acetonitrile wasbrushed on paper. The solvent evaporated in a few seconds. The residuewas visible under a UV lamp, and showed a brilliant blue image afterbrief exposure to bromine vapor or a dilute solution of an oxidant suchas N-bromosuccinimide.

What is claimed is:
 1. A compound having the formula: ##STR32##wherein Xand Y are selected from --COO (lower alkyl) or --CO (lower alkyl); L andQ are independently selected from --COO (lower alkyl) or --CO (loweralkyl) or pairwise from --H and nitro, lower alkyl and nitro, hydrogenand lower alkyl sulfono, or lower alkyl and lower alkyl sulfono; and M+is one equivalent of an inert cation.
 2. A compound of claim 1 havingthe formula: ##STR33##
 3. A compound having the formula: wherein X and Yare selected from --COO (lower alkyl) or --CO (lower alkyl); L and Q areindependently selected from --COO (lower alkyl) or --CO (lower alkyl) orpairwise from --H and nitro, lower alkyl and nitro, hydrogen and loweralkyl sulfono, or lower alkyl and lower alkyl sulfono; and M+ is oneequivalent of an inert cation.
 4. A compound of claim 3 having theformula: ##STR34##
 5. A compound having the formula: ##STR35##wherein Xand Y are selected from --COO (lower alkyl) or --CO (lower alkyl); and Land Q are selected independently from --COO (lower alkyl) or --CO (loweralkyl) or pairwise from --H and nitro, lower alkyl and nitro, hydrogenand lower alkyl sulfono, or lower alkyl and lower alkyl sulfono.
 6. Acompound of claim 5 having the formula: ##STR36##
 7. A compound of claim5 having the formula:
 8. A compound having the formula: wherein X and Yare selected from --COO (lower alkyl) and --CO (lower alkyl).
 9. Acompound of claim 8 having the formula: ##STR37##10.
 10. A method ofmaking a compound having the formula: wherein X and Y are selected from--COO (lower alkyl) or --CO (lower alkyl) and M+ is one equivalent of aninert cation, which comprises contacting and reactingtetrachlorocyclopropene with CH₂ XY in the presence of a strong,non-nucleophilic base in an inert solvent, at a temperature of --50 to100° C.
 11. The method of claim 10 wherein the temperature is from 0° to25° C.
 12. The method of claim 10 wherein the base is sodium hydride.13. A method of making a compound having the formula: ##STR38##wherein Xand Y are selected from --COO (lower alkyl) or --COO (lower alkyl) whichcomprises contacting and reacting tetrachlorocyclopropene with CH₂ XYand N(lower alkyl)₃ in the molar ratio 1:2-3:5-6 in an inert solvent, ata temperature of -50° to 20° C.
 14. A method of making a compound havingthe formula: ##STR39##wherein X and Y are selected from --COO (loweralkyl) or --CO (lower alkyl); L and Q are independently selected from-COO(lower alkyl) or -CO (lower alkyl) or pairwise from -H and nitro,lower alkyl and nitro, hydrogen and lower alkyl sulfono, or lower alkyland lower alkyl sulfono; and M+ is one equivalent of an inert cation,which comprises contacting and reacting ##STR40##with CH₂ (LQ) and astrong, non-nucleophilic base in the molar proportions 1:1-2:2-2.5 in aninert solvent, at a temperature of 0° to 30° C.
 15. The method of claim14 wherein the base is sodium hydride.